Means for breathing mixtures of gases at low temperatures



1941- W. M. BOOTHBY 2,228,502

MEANS FOR-"BREATHING MIXTURES 0F GASES Air-Low TEMPERATURES 7 Filed Dad. '14, 1939 5 Shets-Sheet 1 Inverl'tor-z Y 0 w t lt M PW 0v v 4 5 Jan; 14, 1941. w. M, BQOI'THBY MEAN-5 ,F.0 I1; BREATHING MIXTURES OF egsas AT LOW 'rzmrnnuuaus 5 Shuts-Sheet 2 Filed 'Dec. 14, 1939 Inventor.

Jan. 14, 1941. i w, B-QQTHBY 2,228,502

MEANS FOR anagrams MIXTURES or usas'u- LOW TEMPERATUBS Filed Dec. 14, 19:59 "5 Sheets-Sheqt 3 Walter- M. Boot lab ttornelj lhve ritor'i Jan. l4, 1941. I w BQQTHBY v 2,228,502

MEANS FOKBREATHING-MIX'IURES. OF GASES AT LOW TEMPERATURES:

Filed Dec. 14, 1939 5 Sheets-Sheet 4 1941- w. M. BOOTHBY MEANS FORNBREATHING mxxwunngor easns' AT LOW TEMPERATURES 'Filed Dec; 14, 1959 5 Sheets-Sheet 5 :u Z o n r no 0 W t nM mm w Hm G W Patented Jan. 14, 1941 Qumran STATES PATENT" orrlca azzaso'z MEANS FOR nnm'rnmc MIXTURES or GASES AT LOW 'ramraaaruaas Walter M. maib'anocnesm, Minn.

application December, 14, 19:9, sum No. 309,168

e'cmms. 1(01. 128-203),

My invention relates to means for breathing mixtures of gases at low temperatures and in predetermined proportions, and' is adapted to be used in connection with a. breathing mask and 5 means for delivering to individuals a mixture of gases such as added oxygen mixed with air.

invention provides in eifect valve mechanism of a restriction type for regulating the-inlet of air.

' it will automatically be regulated so that the proportion of oxygen in the mixture of gases actually going to the alveolar regions can be varied at will by merely varying the amount of oxyge as shown by a flow gauge, going to the it 25 apparatus.

The invention is applicable both to the 0mnasal mask wherein both nose and mouth are covered, such as is shown in joint application of myself with Arthur H. Bulbulian and William 0 R. Lovelace, Serial Number 287,087, filed July 28, 1939, or to nasal masks alone, such as shown in joint application of myself, Arthur H. Bulbulian and William-R. Lovelace, Serial Number 287,086, also filed July 28, 1939.

In the structures of the above noted applications and in this application, there is a rebreathing bag the capacity of which is substantially less than the volume of a complete exhalation .or an inhalation of a normal person in normal respiration. Means are there provided for delivering to this rebreathing bag a constant streambf oxygen the volume of which is controlled by wellknown means including a regulator valve and a ,flow valve. It'follows that the rebreathin'g bag will tend to be filling with oxygen at all times, and that the first part of an inhalation will draw into the lungsQthe contents of the rebreathing bag, after which external air with whatever oxy- 4 gen is being delivered will be drawn into the 50 lungs during the latter part of inhalation. .And

on exhalation the-first part of the exhalation which is richestin oxygen and contains the least amountofcarbon dioxide will flow into therebreathing bag and the latter part of exhalation 55 which contains a greater proportion of carbon permit normal breathing of bag, determine the temperatures-minus 60 F. this stored heat will dioxide will go through the mask openings to atmosphere.

I have discovered that if, in place of the me-- chanically controlled inhalation and exhalation valves, I employ a suitably proportioned aperture or apertures for both'exhalation and inhalation and arrange about or over said apertures a sumcient layer of some porous substance through which air going to or from atmosphere on exhalation or inhalation must pass, the slight resistance to breathing which is thus set up will, in conjunction with the flow of oxygen to the rebreathing mixture being breathed, so that the actual proportion of oxygen in the alveolar regions will be related in a predetermined manner to the amount of oxygen being delivered, as shown by proportionpf oxygen in the the flow valve. At the same time the sheet of the porous material through which the air passes on exhalation and inhalation, positioned as it is close to the mouth of the wearer, is to store heat, so breathing may be accomplished at low or even.lower-and prevent freezing of condensed moisture of exhalation.

It is therefore a primary object of my invention to provide a passage to atmosphere from the mask having associated therewith a layer of porous material through which such inhalation and exhalation as may be required will be caused to pass.

I have discovered that an effective material for this purp se is a light and very fine mesh porous sponge rubber invention to arrange between the breathing chamber of the mask and atmosphere a passage norm ly opening to atmosphere having therein or thereabout a-layer of sponge rubber of sumand it is an object of my cient thickness to retain heat sufllciently to prevent any freezing thereon and at the same time to permit free breathing on the part of the'wearer, with only enough restriction to effect,.incon- .junction with the oxygen delivery control shown by the flow valve, proper proportioning of oxygen;

in the a I For aviation purpose tal or military aviation, tudesare frequently reached, the aviator be able to send, as well as receive, radiosignals; It is, therefore, an importantob-' jectof my invention to :arrange the-aforesaid particularly experimen where very high altilayer of .porous material relative tomthe mouth it is'essential that of-the aviator and theradio microphone so that the voice may be transmitted. through the aforesaid porous material to the'radio microphone and of the mask and the face of the wearer, which points of contact at low liarly subject to freezing.

The full objects and advantages of my invention will appear in' connection with the detailed description thereof now to be given, and the novel features by which the indicated advantageous results are secured will be particularly pointed out in the claims, it being understood that the particular forms of the invention shown temperatures are pecuand described may be varied within the scope of the invention as recited in the claims.

In'the drawings illustrating applications of invention as recited in the claims: Fig. 1 is a view of a preferred form of the invention as it appears upon the head of the wearer.

Fig. 2 is an inside view of the mask proper without the enveloping holding means. Fig.3 is a sectional view on line 3-3 of Fig. 2. Fig. 4 is a fragmentary sectional view through one of the tubes at the side of the mask showing the manner of plugging the tube to prevent accumulations of moisture there if Fig. 5 is a side elevation view of the mask as shown in Fig. 2.

Fig.6 is a sectional view taken on line 6-5 of Fig. 2 viewed in the direction of the arrows.

Fig. 7 is-a sectional view taken on line 1-1 of Fig. 6 viewed in the direction of the arrows.

Fig. 8 is a diagrammatic showing of a source of oxygen supply and regulating valve and fiow' meter used in the connection thereto.

Fig. 9 is a view of a modified form of the invention as applied to the head of a wearer show-- ing a modified form of the invention.

Fig. 10 is a view similar to Fig. 9 taken in iongitudinal section through the mask and parts connected therewith.

Fig. 11 is a sectional view taken on line ll-l I. of Fig. 10. F

Fig. l2is a sectional view takenv through the. cylinder of porous material protecting the pass sage to atmosphere.

parts in section showing the applicationlof my invention to a nasal mask. Fig. 14 is a central section through the mask proper.

Fig. 15 is a section on line l5 l5 of Fig. 14. Fig. 16 is a front view of a form of oronasal mask somewhat modified over that shown in Figs. 1 to 7. Fig. 17 is a sectional view taken on line I1l1 Fig. 13 is a view similar to Fig. 9 with some of Fig. 16 viewed in the direction of the arrows.

Fig. 18 shows a form of device applicable to a nasal mask taken on line "-43 of Fig. 19.

Fig. 19 is a sectional view taken on line l3-l3 of Fig. 18.

Referring first to Figs. 1 to '1 inclusive, which is a particularly advantageous form of oronasal mask for aviation purposes, the mask proper comprises a pair of tubes l0 and H extending.

into a nose-receiving extension l2 which, as'

. neath the nostrils when the device is worn, see

Fig. '1. The'tubes Ill and II unite in a transverse section 2I which is adapted to-engage the chin of the wearer. Web l3, Fig. 3, is provided with an opening 22 which leads into the tubular extension 23, Figs. 5 and 7. The tubular extension will be of relatively solid and stiff rubber and is provided with an expanded rim 24 adapted to receive the neck 25 of a rebreathing bag". The neck 25 will preferably be additionally reinforced by a rim of rubber 21 and when said neck has beenforced over the extension 24 of tube 23, it will be held in position thereon with the rebreathing bag very close to the breathing chamberv 28 adjacent the mouth and nostrils of the wearer.

, An opening 29 extends from chamber 28, see

Figs. 4 and 7, into the turret-like extension 30 which is preferably formed with a conical portion 3| united directly with the web I 8 and with a cylindrical portion 32 extending therefrom, and a turned over annular lip portion 33, leaving an opening 34 to atmosphere, as best shown in Figs. 3 and 7. Within the extension 30, as clearly shown in Figs. 3 and 7, is positioned an insulating stiffening ferrule 35 of material such as hard rubber-or any heat-insulating composition, formed with an annular flange 36 which provides an opening 31 into the chamber formed by the conical portion 3| of turret 30. The ferrule 35 rests at 33 upon the outward innerlimits of the conical portion 3| and the outer margins of ferrule 35 engage the intumed lip portion 33 of member 30. Within the ferrule 35 and held positioned between the fiange 33 thereon and lip portion 33 is a cylindrical pad 39 of porous material, specifically of sponge rubber, which is thus held between the openings 31 from chamber 28 and the opening 34 to atmosphere. J

The rebreathing bag 26 is supplied with oxygen from a delivery tube ll going to an oxygen tank various points along the tube extension 44. And

since the rebreathing bag may be used in air of I extremely low temperature, it is essential that it be composed of a type of rubber which will not freeze or stiffen at such'low temperatures.

I Air entering the breathing chamber on inhalation and exhalation gases going to atmosphere is thuscaused to pass through thislayer of sponge rubber of suitably proportioned thickness and fineness of mesh. The sponge rubber is of such a degree of fineness that air will not begin to pass through it in either direction until the flexible rubber rebreathing bag has been entirely emptied or entirely filled, which .never would be true where openings go directly to atmosphere. and'which makes possible theproviout. the necessity of valve regulation for different elevations, which is required where openings go directly to atmosphere.

As shown in Figs. 9 and 10, an oronasal mask 41 is adapted to the wearer, beingheld in position by adjustable strap members 48, 48, connected with the mask through a connector piece 58. This provides a breathing chamber 5I enclosing the nostrils and mouth of the wearer, with a tubular extension 52 leading therefrom, in which drical preferably non-metallic connector piece 53-to which the rebreathing bag 25 is attached. The connector piece 53 is provided with a multiplicity of apertures 54, as clearly shown in Figs. 10 and 11, which may be of any desired number and shape, but preferably are circular and are distributed in a band entirely around the connector piece 53.

Surrounding the connector piece 58 is a cylinder 55 of porous material which will permit passage of .air from and to atmosphere through it upon inhalation and exhalation of the wearer. I have discovered that the material best suited for this cylinder, as is true of pad 39 in the form of the invention above described, is a form of light and very fine mesh porous sponge rubber. From numerous experimental tests I'have discovered that sponge rubber will permit passage of air through it without seriously impeding or overloading the respiratory efforts, and at the same time has the property of retaining the heat brought'to it by the exhalations, so that the en-- tire cylinder'55, or the .pad 38, will become warmedto such an extent that its surface will always be at a. temperature above freezing and hence frost cannot accumulate upon its surface even at such low temperatures as 60 below zero F.

In the form of the invention as detailed in Fig. 7, the gases of inhalation and exhalation 'move directly through the pad 39 through openings 34 and 31. In the form shown in detail in Fig. 10, the gases of inhalation and exhalation move through the openings 54 in connector 53 and thence in radially-expanding directions to the outside of the cylinder to atmosphere, or.

on inhalation in reverse manner.

The detailed form of the inclosing cylinder 55 is shown in Fig. l2, wherein a central cylindrical bore 56 is provided with an expanded conical part 51 which adapts the device to be seated at 58 against the lip 580i the mask casing 41 and against the outer portion 68 of extension 52, thus firmly sealing the device in. At the same-time the lower part of cylindrical bore 58 surrounds the expanded bead SI at the bottom of the connector piece 53, as indicated at 52, Fig. 10, and

holds the cylinder 55 firmly in position thereon.

As shown in Figs. 13 to 15, a nasal mask provides a casing 83 which forms a breathing chamber 64 inclosing the nose of the wearer. 'Tubes.

65 and 66, Fig. 1'5,'pass from breathing chamber 63 about the mouth of the wearer, as clearly indicated in Figs. 13 and. 14, to a central connecting tube 81 from which extends a tube 88 going to metallic connector piece 53 in exactly the same manner as heretofore described for, the oronasal mask 41. A cylinder of sponge rubber 59, surrounds the connector piece .53 and its apertures 54 in exactly'the same manner as already described for the oronasal mask, except that the I cylindrical member 58 does not have the conical expansion-51 from the central bore 56. Operaenclose the mouth and nose .of

is seated a cylin- 1 piece" tively the constructions, of Figs. 10 and'13 are identicalexcept that the breathing chamber 5| of the oronasal mask 54 of the nasal mask structure includes only the nose of the wearer, leaving the mouth free. Howbecomes heated'from the heat of exhalation and prevents freezing even at excessively low temperatures.

As shown in Figs.

41 is shown with piece I8 entering the tubular extension 52 which has an expanded portion "II connecting directly with the neck 12 of the rebreathing bag 28,. A

16 and 17 the oronasal mask circular opening I3 is formed through the casing- 1 of oronasal mask I4 so as to provide a circular flange I5 about said opening. A circular metallic structure includes the mouth and nose, whereas the breathing chambera modified form of connector holder piece 15 is provided with spaced parallel annular flanges I1 and 18 with an intervening groove 18, Figs..17 and 18, said groove preferably having one annular wall obliquely disposed, as indicatedat 88. The holder piece is thus adapted to receive the annular edge 8| surrounding the circular opening I3 into breathing chamber 5I. The circular holder piece 15 is provided with inwardly turned annular flanges 82 and 88, a special flange corresponding in position to flange -82 having an inwardly beveled face 85, Fig. 17.

' There is thus formed through the holder piece I8 9. pair of circular openings 86 and 81. Within the annular channel of the holder piece 18 formed by flanges 83 and 84 of Fig. 17, is'positioned acircular .disc 88 of porous material, in practice, sponge rubber.

this disc of rubber may be slightlycompressed by means of a washer 88 back of it which holds its edges extended into the space behind the beveled faces 85, as indicated at 98 in Fig. 17. e

As shown in Figs. 19 and 20, a circular opening 98 in the front wall of the nasal mask breathing chamber 84, comes substantially below the nostrils of the wearer. Obviously the circular edge I88 of the opening may be caused to engage In the form of Fig. 1'7,

within the annular groove formed between flange members 11, I8 on the cylindrical holding member I5, thus permitting this form of holding -member and any'form of sponge rubber pad carried thereby to be employed in connection with the nasal mask. As shown in Fig. 18, a special iholder piece 98 is provided with annular flanges IN and I82. These flanges are adapted to receive between them the edge of a button I85 of sponge rubber. The edges are then crimped in, as shown in Fig. 18, compacting the sponge rubber between them in the resulting annular V- shaped "groove I88 so that there appears to be an annular extension the pad 88, illustrated in Fig. 17, so that the smaller cross sectional diameter of the pad I85 I84 of similar shape formed about the button .01 pad I85 of sponge rubber I This pad will preferably be of com-.

will have something the same effectin accumulating heat from true of thepad Land also will affect the breaththe breathing exhalations as is 75 the strip I06 ing on inhalation and exhalation in about the same way.

-It will be noted that in the formsof the device shown in Figs 1 to 7, and in Figs. 17 and 18, the pad of sponge rubber and the opening to it through the surrounding casing for holding the pad in positionare directly in front of the mouth of the wearer. Also the circumferential area of opening through these holders, either the holder 30 of Fig. 3 or the button device 18 of Figs. 17 and 18, are proportioned to the size of a radio microphone. I have discovered that with a sponge rubber member so positioned, the speech of the operator will be freely transmitted through the sponge rubber to the radio microphone, thus enabling the aviator to wear the oronasal mask completely inclosing his mouth, and yet be able to freely use the microphone for radio transmission in the same manner as he would be able to do if his mouth .were exposed, as for example, in the use of the nasal mask structure shown in Fig. 13. This is,a highly important feature of my invention, as in very high flying, and particularly in military aviation, it would be impractical to use the nasal mask with the mouth exposed,

for the reason that conditions might arise where the aviator would forget to breathe through the nose and breathe through the mouth, with the result that insufficient oxygen might cause distress or possible loss of consciousness.

Since the masks herein described are designed for aviation at high altitudes and in very low temperatures and also for military aviation, I have discovered that it is of importance to secure the mask, whichever form is employed, and

its attached parts, to the face of the wearer in such manner that all possibility of displacement 'no matter what the contingencies of movement or shock might be, will be eliminated. It is also in a high degree desirable to protect the face of the wearer, particularly at the points where the margins of the mask engage the face, so as to prevent freezing of the face at low temperatures.

I have discovered that both of these \valuable, even essential, features can be obtained by the means shown in Fig. 1, as applied to the form of ornonasal mask disclosed in Figs. 1 to 7 inclusive. This means comprises a strip I06 of sponge rubber having at its front an opening I01 through which the turret extension 80 is adapted to protrude and which aids in holding in position; The strip is provided with portions I08 which overlie the cheeks of the wearer, as clearly shown in Fig. 1. An upper head-encircling strap III! is secured at H0 to the outside of the cheek-overlying portions I08 and will be preferably of elastic material and of such size that it can be pulled down over the head to a position just over the ears where it will retain its position by natural elasticity and,

tend to pull the mask tightly against the face of the wearer. A-second strap-ill will be secured at I to one cheek-overlying portion 10! toward the bottom thereof and a cooperating strap, l I 3 will be adiustably united by fastener members I H in the same manner as indicated in Figs. 9 and 13. s

From the above it will be observed that the member I06 not only will hold'the mask attached to the face of the wearer in such manner that no expected degree of movement or shock can displace it, but at the same time w1l1 cause all of the margins of the mask which contact the face of the wearer, notably those margins which 2,228,502 at lli'of Fig. 1 contact the upper part of the heat from the parts its contacts, this would be very likely to happen.

The advantages of my invention will be apparent from the foregoing description, both in its use clinically and in its use at low temperatures in aviation. In respect to the first of these uses, the greatest difilculty has been experienced heretofore in the administration of gases mixed with air, either oxygen or other gases. in regulating the introduction of air relatively to the amount of added oxygen (or other gases) so that the proportions of oxygen and air in the alveolar regions of the lungs will be those desired. There has been further difllculty in obtaining anything like accurate indications of the true proportions of oxygen in the gas mixture in the alveolar regions. Adjustable mechanical air admission valves have not proved effective for that purpose, resulting in uncertainty as to the alveolar air mixture and to waste of oxygen or other gases added to-the air.

It is therefore, of the highest advantagein the use of my invention that causing movement of gases'to and from atmosphere to go through a layer of sponge rubber provides means for automatically adjusting the proportions of air introduced to'the proportion of oxygen added, so that inspection of the fiow gauge showing the volume of oxygen beingdelivered will correctly inform the operator of the proportion of oxygen, after admixture of air breathed with the oxygen, in the gas mixture in the alveolar passages. That is, where the flow meter indicates a proportion of 20% oxygen in the alveolar gas mixture, that percentage will be there. And when the volume owing to their intimate contact with the moist surfaces within the lugs, are heavily charged with water vapor and may be substantially saturated, and this is at or near the temperature of the body, When such gases pass on exhalation into air at low temperature, the water vapor will necessarily be condensed out of exhaled air-and tends to freeze immediately and to accumulate as frost or ice on surfaces adjacent the point of exhalation, which surfaces have a temperature at or below the freezing point. In inhalation devices for providing breathing of a mixture of gases such as oxygen and air, where necessarily orifices to atmopshere must be of limited area, it follows that accumulations of frost and ice might very quickly render the device wholly inoperative.

. In all of the forms heretofore described, there is provided in conjunction with the opening from the apparatus to atmosphere, a sufficiently thick layer of porous material, specifically sponge rubber, through which the gases of' exhalation and inhalation must pass to and from atmosphere. Because the porous material is by its nature a heat insulator, and for that reason because it tends to accumulate heat and build up a maintained temperature within its body which carries to its surface exposed to atmosphere, the condensation of moisture at the surface of the sponge rubber protector never can reach the freezing point even when atmospheric air is being drawn through it. In other words, the protector layer of sponge rubber is a heat storing device as well as an insulator, and at all times when in normal operation, even at temperatures of 50 to 60 F. below zero, or lower temperatures, it will maintain a suflicient supply of heat to prevent the formation of frost or ice at its surface, thus always maintaining the necessary communication with atmosphere for such 'part of exhalation which mustgo to atmosphere and of inhalation which must comev from atmosphere;

This is a. great advantage over prior devices which have valve mechanism that has to be mechanically regulated as higher temperatures are the arrangement of this sponge rubber protector,

or heat accumulator, in such manner related in position to the mouth of the wearer, and having the sponge rubber pad and the opening to atmosphere which it closes of such size and shape,

that whenwearing the oronasai mask with the nose and mouth completely inclosed the device a none the less enables the aviator to transmit speech to the radio microphone without difliculty.

A further great advantage, .when the mask is used at very low temperatures, is the provision of means for protecting the face of the wearer and particularly the face at points of contact with the oronasal mask structures, so as to insure against freezing the face, particularly at such points, said means also operatingto securely hold the mask structure to the face of the wearer in such manner as to insure against displacement therefrom. I

Iclaim:

1. In combination with a iebreaithing bag and means for delivering oxygen thereto including a regulating valve and a flow meter, said rebreathing bag having a maximum volume less than the volume of a normal inhalation and exhalation whereby part of every inhalation and exhalation must go to atmosphere, an inhalation device comprising a casing forming a breathing chamber connected with said rebreathing bag, means forming an opening from the breathing chamber to atmosphere, and a layer of porous material such as sponge rubber between said opening through which air must pass to atmosphere onfinhalation and exhalation.

2. An inhalation device for breathing mixtures of gases, comprising a casing forming a breathing chamber, a rebre'athing bag connected therewith of less than the volume of a normal inhalation or, exhalation, whereby part of every inhalation and exhalation must go to atmosphere, means forming an opening close to the mouth of the wearer and leading from the breathing,

porous ma'teriai such as sponge rubber over said opening through which air must pass to atmosphere on inhalation and exhalation, and means to control the volume of flow of oxygen to the rebreathing bag as shown by the flowmeter, the

cooperation of said oxygendelivery and passage to atmosphere through the sponge rubber operating to automatically regulate the proportion of oxygen in the alveolar passageways.

4. A mask for breathing mixtures of gases comprising a casing having its open side formed with a transversely and longitudinally curved top portion and an open side, the margins of sa'id open side embodying tubular portions adapted to engage the cheeks and sub-labial portion of the ohm or the wearer, said tubes being open to the breathing-chamber formed by the casing, said casing formed to provide a nose-receiving chamber and a mouth chamber, a turret extending outwardly from the top portion or the casing-and opening therethrough into the mouth chamber, and a removable pad of sponge rubber within the turret throughwhich air of inhalation and exhalation must pass.

5. An inhalation device for breathing mixtures of gases, wmprising a casing forming a breathing chamber, a r'ebreathing bag having a volume.

less than the volume of an exhalation or inhalation in normal breathing, connected therewith,

an opening to atmosphere passing directly from sponge rubber oversaid opening through which air must pass on inhalation and exhalation, and means for holding said mask on the face of the wearer and protecting the face at its points of.

contact with the margins of the mask, including a sheet of sponge rubber overlying the mask and the face at the face-connecting margins of the mask, with an opening in said sheet formed in conjunction with the opening in the mask to atmosphere. WALTER M. BOO'I'HBY. 

